This application supports a research program designed to establish whether or not the use of fast neutron beams in therapeutic radiology can yield significantly superior results to those obtained by megavoltage photon beams and to develop a practical and economically feasible fast neutron therapy facility. Sound evidence from basic radiation biology research indicates that fast neutron and other high LET radiations should be more effective than photon beams in controlling cancer which contains some hypoxic cells. The N.R.L. cyclotron has an ideal neutron beam now operational with sufficient energy and flux for the investigators to employ techniques comparable to megavoltage photons. Adequate physical and biological studies are complete, although further studies are in progress and more are anticipated. This grant request is for support of the completion of a pilot study with cancer patients to establish desirable treatment schedules, dosages and techniques, which will be used in the next phase, a controlled clinical trial. Preparation for this phase, including protocol development will also be completed during the pilot study phase. As no one institution has sufficient clinical material to carry out such an investigation, a collaborative effort between several therapeutic radiology departments in the middle eastern section of the United States has been initiated. Radiation therapists from the centers planning this collaborative effort have met and communicated regularly. The therapeutic radiologists from each institution will be instrumental in developing the randomized study.